Synthesis and photoactivity enhancement of ZnWO4 photocatalysts doped with chlorine

ZnWO4 photocatalysts doped with chlorine were synthesized by a simple hydrothermal process. The influences of chlorine doping on the crystal structure, optical properties and photocatalytic activities of the ZnWO4 photocatalyst were investigated. ZnWO4 doped with chlorine showed enhanced photocatalytic activity for the degradation of methylene blue (MB), rhodamine B and 4-chlorophenol. The photocatalytic activity of ZnWO4 with RCl = 0.3 can be enhanced approximately 4 times for the degradation of MB. The enhanced photocatalytic activity originated from the increase of the transfer rate of photogenerated electrons to the photocatalyst surface, which was promoted by chlorine doping. The photodegradation process of MB can be described as N-demethylation and oxidative degradation. In the case of chlorine doping, an effective separation of the photogenerated electron–hole pairs and the fast interfacial charge transfer to the electron donor/electron acceptor occurred.